DEEP SEA FISHES (il 



Tho visitor should next inspect tlic cases of sluirks which arc situated 



near the entrance hall on the south side. These inchide 

 Sharks ... «. i i i i ■ • i i 



\ arious torms oi sharks and rays, selected as typical ineinhers 



of this ancient ^roup — for the sharks have mnncrous characters which 



put them in the ancestral line of all other groups of fishes. 



Next to be visited are the silver sharks or (^hiniwroids, which arc ex- 

 hibited by the side of the lamprey case. They are now known to l)e liighly 

 modified sharks: their scales have failed to develop, and their heavy " teeth " 

 appear to represent many teeth fused together. These fishes are now very 

 rare and, with few exceptions, occur in the deep sea. The present models 

 show the characteristic forms. 



The adjacent case (at the left) pictures the three types of sur\i\ing 

 ^ , lungfishes, and the models are arranged to indicate the life 



Lungfish , ,^ ,. , . . p rr., 



habits 01 these mterestmg forms. Ihus, they are shown 

 going to the surface of the water to breathe; and their poses indicate that 

 they use their paired fins just as a salamander uses its arms and legs. In 

 fact there is reason to believe that the land -living vertebrates are descended 

 from forms closely related to lungfishes. One sees in this case also a "co- 

 coon," in which the African lungfish passes the months when the streams 

 are dried up and during which time it breathes only by its lungs. 



One now passes into the north aisle of the fish gallery and stops at the 

 . first case on the left. Here appear all types of existing 



Ganoids. These are fishes that represent, as it were, a 

 half-w^ay station between lungfishes and sharks on the one hand, and the 

 great tribe of bony fishes on the other — such as perches, basses, cod, etc. 

 In this case one sees gar pikes, sturgeons, the mudfish (Amia), together 

 with the African Bichir, a curious Ganoid encased in bony scales and re- 

 taining structures which bring it close to the ancestral sharks. A further 

 glimpse of the Ganoids may now be had by returning near the entrance of 

 the fish hall and viewing the spoonbill sturgeon (paddlcfish) group, in 

 which a number of these eccentric fishes are show^n side by side wdth gar 

 pikes and other characteristic forms from the Low^r Mississippi. This 

 group w^as secured through the Dodge Fund. 



Returning then to the north wing of the gallery the remaining cases 



give characteristic examples of the various groups of modern 



"bony fishes," or Teleosts. There are twenty -six cases of 

 them in all, but they oflFer little space in which to illustrate the 10,500 

 species. For these are the fishes which are dominant in the present age, 

 contributing over nine-tenths of all existing forms and including nearly all 



food and game fishes, such as bass, cod, eel and herring. One 

 p. , of the cases of the Teleosts exhibits the grotesque fishes from 



deep water, in which they occur to the surprising depth of 



